The present invention relates to filters for liquids, more particularly for liquids contained in tanks. The inventive filter draws liquid from near the surface, where it is least contaminated. The filter is self-cleaning and will not become fouled on internal pipes in the tank. Most inportantly, the filter of the present invention is inexpensive to construct and can be installed very quickly for a low price. It is especially suitable for installation in home heating oil tanks.
Overhiser (U.S. Pat. No. 880,240) discloses a filter that may be somewhat self-cleaning and will not become fouled on tank internals. However, this filter is far more expensive to make and install than that of the present invention.
Breese (U.S. Pat. No. 318,689) discloses a floating filter that draws liquid from near the surface. However, this filter would tend to become fouled on tank internals. Furthermore, the filter of Breese is not as self-cleaning as that of the present invention.
Neumann (U.S. Pat. No. 1,647,808) and Traulsen et al (U.S. Pat. No. 882,030) disclose floating filters with guide means to prevent fouling. However, these filters are far more complicated to install than those of the present invention and are not as self-cleaning.
The present invention provides a floating filter capable of extremely rapid and inexpensive installation on tanks having an existing opening in their tops. It is especially suitable for home heating oil tanks. Once installed, the filter will not become fouled on internal pipes in the tank and is expected to never require cleaning. This is highly favorable compared to the in-line filters presently in home-heating-oil use, which require cleaning annually or more often.